Puerarin attenuates cisplatin-induced apoptosis of hair cells through the mitochondrial apoptotic pathway

ABSTRACTTo survive and replicate within a host, many viruses have evolved strategies that target crucial components within the apoptotic cascade, leading to either inhibition or induction of cell apoptosis. Enterovirus 71 (EV71) infections have been demonstrated to impact the mitochondrial apoptotic pathway and induce apoptosis in many cell lines. However, the detailed mechanism of EV71-induced apoptosis remains to be elucidated. In this study, we report that EV71 2B protein (2B) localized to the mitochondria and induced cell apoptosis by interacting directly with and activating the proapoptotic protein Bax. 2B recruited Bax to the mitochondria and induced Bax conformational activation. In addition, mitochondria isolated from 2B-expressing cells that were treated with a recombinant Bax showed increased Bax interaction and cytochromec(Cytc) release. Importantly, apoptosis in cells with either EV71 infection or 2B expression was dramatically reduced in Bax knockdown cells but not in Bak knockdown cells, suggesting that Bax played a pivotal role in EV71- or 2B-induced apoptosis. Further studies indicate that a hydrophobic region of 18 amino acids (aa) in the C-terminal region of 2B (aa 63 to 80) was responsible for the location of 2B in the mitochondria. A hydrophilic region of 14 aa in the N-terminal region of 2B was functional in Bax interaction and its subsequent activation. Moreover, overexpression of the antiapoptotic protein Bcl-XLabrogates 2B-induced release of Cytcand caspase activation. Therefore, this study provides direct evidence that EV71 2B induces cell apoptosis and impacts the mitochondrial apoptotic pathway by directly modulating the redistribution and activation of proapoptotic protein Bax.IMPORTANCEEV71 infections are usually accompanied by severe neurological complications. It has also been postulated that the induction of cell apoptosis resulting from tissue damage is a possible process of EV71-related pathogenesis. In this study, we report that EV71 2B protein (2B) localized to the mitochondria and induced cell apoptosis by interacting directly with and activating the proapoptotic protein Bax. This study provides evidence that EV71 induces cell apoptosis by modulating Bax activation and reveals important clues regarding the mechanism of Cytcrelease and mitochondrial permeabilization during EV71 infection.

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Hyaluronan suppresses lidocaine-induced apoptosis of human chondrocytes in vitro by inhibiting the p53-dependent mitochondrial apoptotic pathway

Acta Pharmacologica Sinica ◽

10.1038/aps.2015.151 ◽

2016 ◽

Vol 37 (5) ◽

pp. 664-673 ◽

Cited By ~ 14

Author(s):

Yoon-Jin Lee ◽

Soo A Kim ◽

Sang-Han Lee

Keyword(s):

Human Chondrocytes ◽

Apoptotic Pathway ◽

Mitochondrial Apoptotic Pathway ◽

Induced Apoptosis

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CRISPR/Cas9 Knockout of Bak Mediates Bax Translocation to Mitochondria in response to TNFα/CHX-induced Apoptosis

BioMed Research International ◽

10.1155/2019/9071297 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Jingtian Zhang ◽

Han Niu ◽

Zhizhuang Joe Zhao ◽

Xueqi Fu ◽

Yuxiang Wang ◽

...

Keyword(s):

Cell Line ◽

Parp Cleavage ◽

Caspase 8 ◽

Caspase Activation ◽

Apoptotic Pathway ◽

Mitochondrial Apoptotic Pathway ◽

Apoptotic Protein ◽

Induced Apoptosis

TNFα/CHX-induced apoptosis is dependent on caspase-8 activation and regulated by Bcl-2. However, the specific participants and precise mechanisms underlying this apoptotic pathway are poorly understood. The proapoptotic proteins Bak and Bax—members of the Bcl-2 family—are essential for the functioning of the mitochondrial apoptotic pathway. In this study, we used the CRISPR/Cas9 system to knockout Bak in the human SH-SY5Y cell line and determined the effects of this knockout on TNFα/CHX-induced apoptosis. Our data showed that overexpression of Bcl-2 dramatically prevented TNFα/CHX-induced apoptosis, and then pro-apoptotic protein Bak was downregulated and became more resistant to TNFα/CHX-induced apoptosis, because both TNFα/CHX-induced PARP cleavage and caspase activation were blocked in BAK−/− cells or using specific siRNA, whereas Bax was dispensable in TNFα/CHX-induced apoptosis, as evidenced using specific siRNA. Bax translocated from the cytosol into the mitochondria in response to TNFα/CHX, and CRISPR/Cas9 knockout of Bak significantly decreased this translocation. These results indicate that TNFα/CHX-induced apoptosis does not occur in Bak−/− cells, suggesting that TNFα/CHX-induced apoptosis is Bak-dependent but Bax-independent.

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Thymidine-dependent attenuation of the mitochondrial apoptotic pathway in adenosine-induced apoptosis of HL-60 cells

Journal of Cancer Research and Clinical Oncology ◽

10.1007/s004320100264 ◽

2001 ◽

Vol 127 (9) ◽

pp. 570-576 ◽

Cited By ~ 8

Author(s):

Chang-Mo Kang ◽

Yousin Suh ◽

Ik-Soon Jang ◽

Sang Park

Keyword(s):

Apoptotic Pathway ◽

Mitochondrial Apoptotic Pathway ◽

Induced Apoptosis

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The ER Stress-Mediated Mitochondrial Apoptotic Pathway and MAPKs Modulate Tachypacing-Induced Apoptosis in HL-1 Atrial Myocytes

PLoS ONE ◽

10.1371/journal.pone.0117567 ◽

2015 ◽

Vol 10 (2) ◽

pp. e0117567 ◽

Cited By ~ 11

Author(s):

Jiaojiao Shi ◽

Qi Jiang ◽

Xiangwei Ding ◽

Wenhua Xu ◽

Dao W. Wang ◽

...

Keyword(s):

Er Stress ◽

Atrial Myocytes ◽

Apoptotic Pathway ◽

Mitochondrial Apoptotic Pathway ◽

Induced Apoptosis

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Role of Mitochondrial Apoptotic Pathway in Disulfiram/Copper Mixture-Induced Cell Apoptosis in Human B-Lineage Acute Lymphoblastic Leukemia in Vitro

Blood ◽

10.1182/blood.v126.23.4920.4920 ◽

2015 ◽

Vol 126 (23) ◽

pp. 4920-4920

Author(s):

Bing Xu ◽

Manman Deng ◽

Zhiwu Jiang ◽

Jie Li ◽

Kai Chen ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Lymphoblastic Leukemia ◽

Dependent Manner ◽

Apoptotic Pathway ◽

Mitochondrial Apoptotic Pathway ◽

B Lineage ◽

Induced Apoptosis ◽

Dose Dependent ◽

Cytotoxic Mechanism

Abstract Backgrounds: The long term prognosis of adult B-lineage acute lymphoblastic leukemia (B-ALL) is poor when compared with pediatric B-ALL. The current therapeutic regimen for adult B-ALL often results in refractory and relapsing diseases. Therefore, it is urgently needed to explore novel approaches to treat adult B-ALL. Disulfiram (DS) has been used clinically as a safe anti-alcoholism drug for over 6 decades. Recent studies demonstrated that disulfiram/cooper mixture (DS/Cu) was cytotoxic to multiple solid cancers, but its effects on B-ALL cells are still unclear. Moreover, the molecular mechanism of the cytotoxicity of DS/Cu to tumor cells was poorly defined. In this study, we investigated the effects of DS/Cu on B-ALL cells in vitro and its related cytotoxic mechanism. Results: Firstly, CCK8 assay indicated that DS/Cu markedly inhibited Nalm6 cell proliferation in a dose-dependent manner. Secondly, colony-forming assay showed that DS/Cu also abolished the clonogenicity of Nalm6 cells (P<0.001). Thirdly, FACS analyses revealed that DS/Cu mixture could induce apoptosis of Nalm6 cells, as well as primary B-ALL cells (n=16) in a dose-dependent manner. We additionally analyzed the relationship between clinical characteristics of B-ALL patients, including age, WBC counts, immunophenotype, cytogenetics, risk stratification and Ph chromosome, with the efficacy of DS/Cu on B-ALL cells. The apoptosis isolated from pro-B and cytogenetic abnormality B-ALL pastients was higher. Therefore, our results demonstrated that DS/Cu mixture could induce significant cytotoxicity against B-ALL cells in vitro. To decipher the cytotoxic mechanism of DS/Cu mixture, JC-1 staining was done and the results showed that DS/Cu mixture could significantly reduce the mitochondrial membrane potential in Nalm6 cells (P<0.01) and 7 cases of primary B-ALL cells (P<0.05). Consistently, Western Blot analysis showed that DS/Cu induced B-ALL cell apoptosis by down-regulating the expression of anti-apoptotic protein Bcl2 and Bcl-XL, as well as activating caspase-3 and its substrate PARP. Hence, our results indicated that DS/Cu induced apoptosis of B-ALL cells at least partly through the intrinsic mitochondrial apoptotic pathway. Conclusion: Our results demonstrated that DS/Cu not only significantly inhibit proliferation and clonogenicity, but also induce apoptosis of B-ALL cells in vitro.The mitochondrial apoptotic pathway might be the molecular mechanism of DS/Cu-induced apoptosis of B-ALL cells. Disclosures No relevant conflicts of interest to declare.

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